Chariocrinus japonicus, a new species of isocrinid crinoid (Articulata) from the Lower Cretaceous of Takayama City, central Japan

Abstract

A specimen, originally described as ‘Pentacrinus’ from the Middle–Upper Jurassic of central Japan, is re-analysed and now recognised to be a new species of the genus Chariocrinus Hess, 1972, from the Lower Cretaceous. Chariocrinus japonicus sp. nov. has nine columnals per noditaxis, low columnal height, a pentalobate to sub-pentagonal articular facet and an impersistent median ridge on the latera. Chariocrinus was originally described from the Middle Jurassic of Switzerland, and has also been recognised from elsewhere in Europe, Antarctica and North America. The Japanese specimen represents the first report of Chariocrinus in the Cretaceous of Asia, thereby significantly extending both its temporal and eastern geographical range. This specimen suggests Chariocrinus had a global distribution and, as such, conforms with the distribution of other Mesozoic and modern isocrinine gener